1. Field of the Invention
The present invention relates to exercise equipment and more particularly to an exercise apparatus for aiding an exerciser in performing a leg-stretching exercise.
2. Background Art
Leg-stretching exercise is a very popular exercise performed by athletes, gymnasts, martial artists, dancers, sportsmen, and so on, usually on a day basis. The leg-stretching exercise basically comprises alternatively performing the steps of spreading the legs apart to the point of maximum separation and drawing them back together. The act of spreading the legs apart is also known as performing a split.
Usually, an exerciser, while performing the leg-stretching exercise, especially the split, utilizes his/her body weight to push and gradually slide the legs apart while relaxing the muscles thereof. If proper control is not exercised over the same, it leads to, at a minimum, pulling a muscle, which in turn leads to a painful injury. The leg-stretching exercise also entails the exerciser to rise against the weight of his/her body while retracting his/her legs back together. This may cause a certain amount discomfort to the exerciser. Choice of the surface whereon the leg-stretching exercise is performed is another crucial factor. While a rough surface makes it difficult for the exerciser to slide the feet apart, a surface which is too smooth might cause the slippage of the feet leading to, again, a painful injury.
Several exercise apparatuses and devices are known in the art for aiding an exerciser in performing the leg-stretching exercise. Since the leg-stretching exercises are mostly performed on the exercise apparatuses, the aforementioned issue of inappropriate surfaces is taken care of.
U.S. Pat. No. 3,584,871 to Kehnon, Jr. discloses a Push-Pull Type Leg Stretching Device comprising a pair of linearly-displaceable platforms coupled together by a resilient means which enables the platforms to be alternatively extended apart a predetermined distance and drawn back together into an abutting relationship. An exerciser can perform the leg-stretching exercise thereon by placing his/her either foot on the pair of platforms and slide them apart and then draw them back. The resilient means exerts a counter force against the direction of the movement of the platforms while performing the split, thereby relieving the exerciser from the burden of controlling his/her body weight. Also, the resilient means eases the pressure of the body weight on the exerciser while retracting his/her feet owing to the counter force.
However, on the flipside, it is difficult for the exerciser to maintain the balance of the torso thereof on the leg stretching device during the exercise, especially when the exercise is performed in a quicker manner. Another disadvantage is the lack of a means for the feet to prop against so as to prevent the slippage thereof on the platforms.
U.S. Pat. No. 5,518,484 to Bruckenstein discloses a Leg Stretching Device comprising a slidable foot supporting plate mounted on a pair of rails extending between a pair of blocks. An exerciser, in order to perform the leg-stretching exercise, straddles one end of the device, places a foot on the supporting plate and obtains the desired stretch by urging the plate toward the other end. Bruckenstein's device, apart from sharing the torso-imbalance disadvantage of the Kehnon, Jr.'s device is also devoid of the utility offered by a resilient means of the Kehnon, Jr.'s device. Another disadvantage is owing to the single foot supporting plate which is, the exerciser, while performing the split, needs to ensure that the surface on which the Bruckenstein's device is placed should not be too smooth to cause slippage of his/her foot resting thereon.
U.S. Pat. No. 4,132,404 to Wilson discloses a Leg Stretching Exercise Device which is structurally similar in construction to the above discussed Kehnon, Jr's device except that, in the Wilson's invention a non-resilient means is employed in place of the resilient means. Therefore, the disadvantages of Kehnon, Jr's device and the disadvantages of not employing a resilient means apply to the Wilson's device.
Finally, U.S. Pat. No. 5,147,266 to Ricard discloses a Leg Stretching Machine for performing a Chinese split. The leg stretching machine comprises a base, two generally horizontal tracks extending collinearly from the base, a foot platform sliding on each track, and a vertical column with handles. The exerciser stands on the platforms, which travel outward from the base while the split is performed and maintains the balance by holding handles. The platforms are moved along the tracks by cables fixed on either side of each platform. The cables run over pulleys to a drum mounted in the column, which can be turned by a crank.
Although the Ricard's leg stretching machine enables an exerciser to balance the torso thereof by employing a column with handles to grab on to, and a mechanism of cables for dealing with the body weight, it is bulky, complex in construction. Also, the Ricard's machine is particularly designed for performing a Chinese split and therefore cannot be ideal for the leg-stretching exercise, where the exerciser may need to alternatively stretch and retract the legs in a quicker manner. Yet another disadvantage of the Ricard's machine is that the exerciser needs to control the displacement of the foot platform by operating the crank while performing a split, which is an additional task for the exerciser.